For the purposes of this Section, where there is a reference to a “blank wall,” the following shall apply:

(a)        For manufacturing buildings, the provisions of Type 2 blank walls set forth in Section 37-361 (Blank wall thresholds) shall apply.

(b)        For commercial buildings, community facility buildings and mixed buildings, the provisions of Type 3 blank walls set forth in Section 37-361 shall apply.

(c)        For residential buildings, the provisions of Type 4 blank walls set forth in Section 37-361 shall apply.

Such blank walls shall be covered by one or more options in Section 37-362 (Mitigation elements) or by options as described in this Section, inclusive. In addition, any surface area of a wall which bounds stairs, ramps, landings, or chair lifts facing a street and that exceeds a height and width of four feet shall constitute a blank wall and comply with the standards of Type 3 blank wall. Such blank wall surfaces shall be calculated between the level of the adjoining sidewalk and the level of the first story above the flood elevation. In addition, any surface area of a wall which bounds stairs, ramps, landings, or chair lifts facing a street and that exceeds a height and width of four feet shall constitute a blank wall and comply with the standards of Type 3 blank wall. Such blank wall surfaces shall be calculated between the level of the adjoining sidewalk and the level of the first story above the flood elevation.